Diagnosis device and diagnosis method

ABSTRACT

The present invention provides a diagnostic device that presents, to a patient, a Noise-Vocoded Speech Sound signal that is obtained by dividing at least one portion of a sound signal into a single or a plurality of frequency band signals and subjecting the frequency band signals to noise, and analyzing the content of a response recognized by the patient and the presented stimulus to diagnose a disease of the patient based on the analysis results, so that diagnosis including determining the disease of the patient and estimating a damaged site can be performed.

TECHNICAL FIELD

The present invention relates to a diagnostic device that employNoise-Vocoded Speech Sound obtained by subjecting at least one frequencyband signal of a sound signal to noise and a method thereof. Inparticular, the present invention relates to devices and methodssuitable for diagnosis of a patient who might suffer from a neuraldisorder.

BACKGROUND ART

Conventionally, a diagnosis to a patient who might have had cerebralinfarction, cerebral hemorrhage or the like is performed, using a X-raycomputerized tomography system, a MRI (magnetic resonance image)tomography system, a positron emission tomography system utilizingpositron emission or the like.

On the other hand, in research on recognition of sound signals, it hascome to be known that a speech can be recognized to a considerableextent without hearing a complete sound signal, that is, even if acomponent of a sound signal is subjected to noise by a certain method.Such a technique is disclosed in, for example, reference 1 (Shannon, R.V., et. al, “Speech Recognition with Primarily Temporal Cues”, SCIENCE,1995, no. 270, pp. 303 to 305), reference 2 (an article of an auditorysense study group of Acoustical Society of Japan, “Speech perceptionbased on temporal amplitude change with spectrally degraded syntheticsound” by Yoshihisa Obata and Hiroshi Rikimaru, 1999, H-99-6), reference3 (an article of an auditory sense study group of Acoustical Society ofJapan, “Intelligibility of synthesized Japanese speech sound made ofband noise—preliminary study for a speech recognition processorutilizing central auditory function—” by Yoshihisa Obata and HiroshiRikimaru, 2000, H-2000-3).

According to such references, a sound signal is divided into fourfrequency bands (0 to 600, 600 to 1500, 1500 to 2500, 2500 to 4000 Hz),each sound signal is subjected to half-wave rectification and is appliedto a 16 Hz lowpass filter so as to obtain an amplitude envelope of eachfrequency band, and is multiplied by a band noise corresponding to eachfrequency band, and the thus obtained signals are added to generate asignal. Such a signal is referred to as “Noise-Vocoded Speech Sound”. Ithas been reported that when people with normal hearing ability heard theNoise-Vocoded Speech Sound, an intelligibility of about 80% wasobtained.

Conventionally, X-ray computerized tomography systems, MRI (magneticresonance image) tomography systems, positron emission tomographysystems utilizing positron emission and the like have been used todiagnose a disease of a patient who might suffer from a neural disorderstemming from cerebral infarction, cerebral hemorrhage or the like.Although the use of these systems is an effective approach to detect aninjured part or a focal part, this approach is an anatomical diagnosisof a disordered site and has a difficulty in diagnosing the function. Ifthere is a simple method for diagnosing the function that cannot beclarified only by anatomical images without using a large scale device,such a method can achieve easy diagnosis. Furthermore, there is also ademand for diagnostic devices for a disorder such as presbycusis,congenital deafness, hearing impairment with independent of the neuraldisorder.

DISCLOSURE OF THE INVENTION

In order to solve the above-described problems, the diagnostic device ofthe present invention adopts the following means and approaches.

(1) The present invention provides a diagnostic device for diagnosing adisease of a patient by presenting, to a patient, a Noise-Vocoded SpeechSound signal obtained by dividing at least one portion of a sound signalinto a single or a plurality of frequency band signals and subjectingthe frequency band signals to noise; analyzing a content of a responserecognized by the patient and the presented stimulus; and diagnosing thedisease of the patient based on the results of the analysis. This isuseful to determine the disease of the patient and to estimate theinjured site.

(2) The Noise-Vocoded Speech Sound signal in which a component of asound source signal is subjected to noise is generated by extracting afrequency band signal with a predetermined frequency band from at leastone portion of the sound source signal by a first band filteringprocedure having a plurality of band filtering procedures; extracting anamplitude envelope of each frequency band signal by an envelopeextracting procedure; generating a frequency band noise signalcorresponding to the predetermined frequency band from a noise sourcesignal by a second band filtering procedure having a plurality of bandfiltering procedures; multiplying the frequency band signal and thefrequency band noise signal in a multiplying procedure; and accumulatingoutputs obtained by the multiplying procedure in an adding procedure. Ifthe number of band filters or the frequency boundary of the frequencybands can be selected or changed, the present invention can be used forvarious diagnostic purposes. Furthermore, with automatic languagerecognition, when the number of band filters or the frequency boundaryof the frequency bands is selected or changed suitably with a language,the present invention can be used by a plurality of peoples withdifferent nationalities, and can be used for diagnosis of people fromabroad.

(3) The above-described diagnostic device can be implemented with theprocedures of a computer program or the like, and therefore can be madeinto a recording medium storing a program that is executed by a computeror a program that is executed by a computer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a Noise Vocoded Speech Sound convertingportion used in one embodiment of the present invention.

FIG. 2 is a block diagram of a diagnostic device according to oneembodiment of the present invention.

FIG. 3 is a block diagram of a Noise Vocoded Speech Sound convertingportion used in one embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of a Noise Vocoded SpeechSound converting portion according to one embodiment of the presentinvention.

FIG. 5 is a flowchart showing the operation of a diagnostic deviceaccording to one embodiment of the present invention.

FIG. 6 is a block diagram of a diagnostic device according to oneembodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the diagnostic device will be described withreference to the accompanying drawings. It should be noted thatcomponents bearing the same reference numeral in the embodiments performthe same operation and may not be described in duplicate.

Embodiment 1

First, a method for generating the Noise Vocoded Speech Sound and aneffect of diagnosis therewith will be described. FIG. 1 is a blockdiagram of a Noise Vocoded Speech Sound converting portion used in thepresent invention. In FIG. 1, a sound signal is applied to a bandfiltering portion 1 via an input terminal 7. The band filtering portion1 has a plurality of band filters 1 a, 1 b, 1 c and 1 d for extractingsignals having a predetermined frequency band. Output signals from theband filters 1 a, 1 b, 1 c and 1 d are applied to envelope extractors 2a, 2 b, 2 c and 2 d, respectively, of an envelope extracting portion 2so that the amplitude envelope of each frequency band signal isextracted. A noise signal output from a noise source 5 is applied to aband filtering portion 4 having a plurality of band filters 4 a, 4 b, 4c and 4 d, to be divided into noise signals having the same frequencybands as those of the band filtering portion 1. The outputs from theenvelope extractors 2 a, 2 b, 2 c and 2 d and the outputs from the bandfilters 4 a, 4 b, 4 c and 4 d are multiplied for each corresponding bandin a multiplying portion 3 having multipliers 3 a, 3 b, 3 c and 3 d. Themultiplied results are summed up in an adding portion 6, and then becomeoutput signals in an output terminal 8.

When a patient was let to hear the Noise Vocoded Speech Sound that isgenerated in this manner and recognized words or sentences are examined,then it was found that there are characteristics in the recognitionresults, depending on the disease of the patient. There are differencesin the recognition results between disorders such as cerebralinfarction, cerebral hemorrhage, presbycusis, congenital deafness,hearing impairment with independent of the neural disorder. It isestimated that a neural function or a neural site used when hearing andrecognizing a sound signal that has been converted to a Noise VocodedSpeech Sound is different from when hearing and recognizing an ordinaryspeech sound, so that the recognition results are unique to eachdisease. By combining the present invention with MR images or the likeas necessary, this phenomenon is utilized for highly accurate diagnosis.

FIG. 2 is a block diagram of the diagnostic device using theNoise-Vocoded Speech Sound of the present invention. The configurationwill be described with reference to FIG. 2. A diagnosis program iscontained in a diagnosis program storing portion 21. The diagnosisprogram refers to a program including a series of procedures, forexample, in which five stimuli, each of which is constituted by a wordor sentence, constitute one set, and the stimuli are presentedsequentially one by one, five words or sentences that are recognizedwhen a patient listened to the Noise Vocoded Speech Sounds thereof areobtained as recognition results, and the disease of the patient isestimated from the recognition results. The number of stimuli is notlimited to 5, and at least one is sufficient. The diagnosis programstores the identification codes of the five stimuli that are to bepresented to a patient and the procedure for presenting the same, andalso stores data for displaying diagnosis procedure and instructions toa patient. A sound source signal storing portion 22 stores sound signalsof various words and sentences for diagnosis that make a pair with theidentification codes. A Noise Vocoded Speech Sound converting portion 23is an element described with reference to FIG. 1, and converts a soundsignal input from a control portion 20 to a Noise Vocoded Speech Soundsignal, which is applied to a headphone 24 so that a patient can hearthe Noise Vocoded Speech Sound through the headphone 24. A displayportion 25 displays data for explanation or instructions for patientssupplied from the control portion 20 with texts or graphics on thescreen. A response input portion 26 is a keyboard with which a word orsentence that is recognized when a patient listened to a Noise VocodedSpeech Sound. The input reaction enters the control portion 20. Amicrophone 27 and a speech recognition device 28 recognize a response orreaction made of speech sounds of the patient, and the response orreaction enters the control portion 20. A response analyzing portion 29analyzes the contents of collected responses and compares the analysisresults with disease database of a disease memory portion 30 to estimatethe disease. A diagnosis output portion 31 outputs diagnosis results,and can be a printer or a display.

Next, the operation of the diagnostic device of the present inventionwill be described.

Upon detection of an instruction to start diagnosis with a startingbutton, the control portion 20 reads out a diagnosis program from thediagnosis program storing portion 21 and sends data for explanation andinstructions for patients to the display portion 25 and lets it displaythe data. Then, the control portion 20 reads out the identification codeof a sound source signal to be presented from the diagnosis program,reads out speed sound signals of a designated word or sentence from thesound source signal portion 22, based on the identification code, andapplies it to the Noise Vocoded Speech Sound converting portion 23. TheNoise Vocoded Speech Sound converting portion 23 converts the soundsignals to Noise Vocoded Speech Sound, which are presented to a patientthrough the headphone 24. The patient inputs the recognized word orsentence when listening to a presented a stimulus to the keyboard of theresponse input portion 26. When it is difficult for the patient to inputby himself, for example, due to damages incurred by the patient, anexaminer or a diagnostician listens to or looks at an answer or reactionof the patient and then inputs. The control portion 20 captures andstores the input response data. The control 20 has obtained a responseto a presented stimulus, and therefore reads out instruction data to bepresented next and the identification code of the sound source signalsfrom the diagnosis program in the diagnosis program storing portion 21,lets the instruction data displayed, lets a stimulus presented, andcaptures and stores response data by the same procedure as above, andthen proceeds with the next stimulus presentation. In this manner, thecontrol portion 20 sends to five sets of response data that are obtainedcorresponding to the five stimuli to the response analyzing portion 29.The response analyzing portion 29 analyzes the response content, usingdisease database that are stored in the disease memory portion 30,estimates the disease, and sends the estimated disease data to thecontrol portion 20. The control portion 20 outputs the estimated diseasename and the disease data from the diagnosis output portion 31.

Next, the mechanism of the diagnosis will be described by taking anexample. Herein, a case of diagnosis of a disease from four diseases,using two sentences as stimuli will be described. A sentence“a-me-ga-fu-ru (which means it rains)” is taken as a first stimulussentence A0. It is assumed that a patient P1 listened to the NoiseVocoded Speech Sound signals of this sentence and gave a responsesentence Al “a-re-ga-ku-ru”. When A0 is compared with A1, “me” and “fu”are recognized as “re” and “ku”, respectively. The vowel sounds arecorrect, but the consonants are incorrect. The manner of making an errordepends on the disease, and response sentences A1, A2, and A3 areobtained, corresponding to three diseases.

There are response sentences B1 to B3 as a result of recognition of asecond stimulus sentence B0 “kyo-u-ha-sa-mu-i” (which means that it iscold today).

In the disease database, a correspondence table is stored in which acorresponding disease of four diseases is allocated to each of 9combinations of the response sentences Ai (i=1 to 3) to the stimulussentence A0 and the response sentences Bj (j=1 to 3) to the stimulussentence B0. The response analyzing portion 29 searches the diseasedatabase based on the obtained responses Ai and Bj, and obtains adisease name Sk (k=1 to 4) corresponding to {Ai, Bj}.

The above example is an example in which four diseases can be identifieddistinctly by searching for a disease name, using responses to the twostimulus sentences as an input function. The format of the diseasedatabase is not limited to the one in the above example.

A variation pair of the stimulus sound and the response sound by theunit of syllable, mora, sound or the like that was an error in eachstimulus sentence may be analyzed in the replay analyzing portion 29,and a set of such variation pairs may be input in the disease databaseas an input function to search for a disease name. The disease databasestores linkage between names of diseases and sets of variation pairs inthe form of a polyvalent function. The input function may includestimulus sentences or identification codes thereof.

As an element of the input function, a stimulus sentence, a responsesentence, a presented sound (correct sound) and a response sound(incorrect sound) in each sentence can be used. As the unit of sounds,the syllable unit, the mora unit, the consonant unit, the vowel unit orthe like can be used. Furthermore, the correlation between the elementas described above and disease name may be represented by a numeralvalue, the sum of correlation values with respect to the input functionor a comprehensive correlation value may be obtained, and a plurality ofdisease names may be selected, starting from the disease name having thelargest correlation value and may be output together with thecorrelation values.

The disease database can be generated by a method in which doctors,speech therapists, audiologists analyze diagnosis results of a largenumber of patients from their experiences, collect responses withrespect to stimulus sentences of a suitable population of patients, andperforms factor analysis of the results.

When responses unique to a specific disease can be obtained withspecific sentences with sound signals that are not be converted to NoiseVocoded Speech Sounds, such sentences can be incorporated in thediagnosis program and incorporated in the database structure.

Embodiment 2

In the above description, the diagnosis program can proceed sequentiallystep by step to supply five stimuli. However, the diagnosis program canbe divided into two steps, and in the first step, a basic diagnosis isperformed, and then, based on the results, the program moves to thesecond step for detailed diagnosis. In this case, when the responseanalyzing portion 29 sends the results of the basic diagnosis to thecontrol portion 20, the control portion 20 selects one from a pluralityof prepared diagnosis programs for the second step, based on theresults, and moves the diagnosis to the second step.

Embodiment 3

A patient may input from the microphone 27 with voice, instead ofinputting from the keyboard, and the voice may be converted to textinformation by the speech recognition portion 28 and be input to thecontrol portion 20.

Embodiment 4

For the frequency bands of the band filters of the band filteringportions 1 and 4 of the Noise Vocoded Speech Sound converting portion23, 0 to 600 Hz, 600 to 1500 Hz, 1500 to 2500 Hz, and 2500 to 4000 Hzare used as the standard frequency bands. As in the Noise Vocoded SpeechSound shown in FIG. 3, a band selecting portion 12 may be provided toswitch the above-described frequency bands of the band filteringportions 1 and 4. For example, the number of frequency bands can beselected among 1, 2, 3, and 4. This is because there is a case in whichthe four frequency bands are not necessary, depending on the words, orthe condition of vowel sounds or consonants. For example, the number ofthe frequency bands can be 2 by setting the output from the band filters1 c, 1 d, 4 c and 4 d to 0. Furthermore, with respect to all or any partof the band filters, the boundary frequency defining the frequency bandscan be switched to other frequencies than 600 Hz, 1500 Hz, 2500 Hz, and4000 Hz. 600 Hz, 1500 Hz, 2500 Hz, and 4000 Hz are close to the standardfrequency boundary that separates the vowel sounds of sound, that is,/a/, /i/, /u/, /e/, and /o/ in Japanese by the first and the secondformants. However, the frequency boundary may be slightly different fromperson to person. An accurate diagnosis may be obtained by adjusting andchanging the boundary of the frequency bands in accordance with such adifference between individuals, so that the device is configured suchthat the boundary can be switched and selected. The number of thefrequency boundary may be larger than 4. Furthermore, foreign languageshave a vowel system different from that of Japanese, so that the devicemay be configured such that the number of the band filters or theboundary frequency can be switched in order to be used with foreignlanguages.

The number of the band filters or the number of the frequency boundarymay be changed according to the diagnosis program, or may be changed inconnection with the disease database.

The microphone may be connected to the control portion 20, and doctors,speech therapists, audiologists or the like may present words orsentences that are not included in the sound source signal storingportion 22 as a stimulus. In this case, ambient noise may be mixed fromthe microphone, so that, as in the Noise Vocoded Speech Sound convertingportion 23 shown in FIG. 3, the sound signal extracting portion 9 isprovided, and only sound components are extracted from input soundsignals and applied to the band filtering portion 1. In order to extractthe sound components, the configuration may be such that ambient noiseother than speech sound components contained in the input sound signalsis suppressed by, for example, a spectrum subtraction technique.

For use with foreign languages, a language automatic recognition portionmay be provided, and words or sentences that have been input first by apatient or a trainer through the microphone 27 may be automaticallyrecognized by the speech recognizing portion 28. Then, the bandselecting portion 12 may set the number of the band filters and thefrequency band boundary corresponding to the language of the country inthe band filtering portion 1 and 4, sound signals with the language ofthe country may be used, and the disease database corresponding to thelanguage of the country may be used.

In order to determine the boundary frequency of the frequency bands, thefrequency characteristics of the language of the pronounced speech areanalyzed, a change of the primary peak of the frequency component isobserved over time, and movement of each formant is detected from thepattern of this change, so that the boundary frequency can bedetermined. In this manner, the boundary frequency that matches thecharacteristics of the pronounced speech of a diagnostician, that is, anexaminer can be used. The Noise Vocoded Speech Sound conversion may beperformed while determining the boundary frequency in real-time. Also inthe case where a boundary frequency corresponding to a foreign languageis used, such a technique for determining a boundary frequency can beused.

Embodiment 5

Signals obtained by converting sound signals to Noise-Vocoded SpeechSounds may be previously stored in the sound source signal storingportion 22 of the diagnostic device of FIG. 2, and a patient may listento an output signal therefrom through the headphone 24. In this case,the Noise Vocoded Speech Sound converting portion 23 may not beprovided.

Embodiment 6

FIG. 6 is a block diagram of a schematic diagnostic device. In FIG. 6, asound source signal storing portion 62 stores sound signal data of wordsand sentences for stimulus presentation. When a diagnostician presses apush button(not shown), a control portion 60 reads out sound signal datafrom the sound source storing portion 62, and applies the same to theNoise Vocoded Speech Sound converting portion 63. The Noise VocodedSpeech Sound converting portion 63 presents the converted Noise VocodedSpeech Sound signal to a patient through a headphone 63. The patientpronounces a recognized word or sentence as a response to thediagnostician. The diagnostician writes down the response and estimatesthe disease from the response results. The diagnostician may pronounce aword or a sentence for presentation through a microphone 67, and thecontrol portion 60 may present the sound data to the patient through theNoise Vocoded Speech Sound converting portion 63 and the headphone 64.In this case, as described in Embodiment 4, as a method for determiningthe boundary frequency of the frequency bands, the following method canbe used: the frequency characteristics of pronounced speech areanalyzed, a change of the primary peak of the frequency component isobserved over time, and movement of each formant is detected from thepattern of this change so that the boundary frequency can be determined.In this manner, the boundary frequency that matches the characteristicsof the pronounced speech of a diagnostician, that is, an examiner can beused.

When a diagnostician orally instructs a patient through the microphone67, a transmission path may be provided to bypass the Noise VocodedSpeech Sound converting portion 63. When Noise Vocoded Speech Soundsignals are stored in the sound source signal storing portion 62, theNoise Vocoded Speech Sound converting portion 63 may be omitted.

Embodiment 7

Hereinafter, an embodiment of the diagnostic method will be described.First, a method for conversion into the Noise Vocoded Speech Sound willbe described. FIG. 4 is an example of a flowchart of the Noise VocodedSpeech Sound conversion. The Noise-Vocoded Speech Sound conversionprocedure (S100) is constituted by steps (S10) to (S15).

First, in the band selection procedure (S10), the number of the bandfrequencies or the boundary frequencies of the band frequencies for bandfiltering that is performed in the band filtering procedures (S11) and(S13) below is changed or set, if necessary. This procedure is performedin response to an operation by a diagnostician or by an instruction fromthe diagnosis program. If there is no such an operation or instruction,this procedure is omitted. Next, in the band filtering procedure (S11),input sound data is filtered, based on the number of the bandfrequencies or the boundary frequency of the band frequencies of theband filtering that are set, to obtain band sound data. In the envelopeextraction procedure (S12), from the filtered sound data, the envelopecomponent data thereof is extracted. Then, in the band filteringprocedure (S13), noise signals of white noise are filtered, according tothe number of the band frequencies or the boundary frequencies of theband frequencies for band filtering that are set, so that band noisesignal data is generated. The envelope component data and the band noisesignal data are multiplied in the following multiplication procedure(S14), and when the multiplication results are obtained for a pluralityof frequency bands, they are accumulated in the adding procedure (S15).The accumulated sound data is Noise-Vocoded Speech Sound data. This ispresented to the patient through the headphone in the form of aDA-converted analog sound signal.

The steps (S10) to (S15) may be performed sequentially according to FIG.4, or may be performed in parallel. These procedures can be realized inthe form of a program of a digital signal processor (DSP).

Next, an embodiment of a diagnostic method will be described. FIG. 5 isan example of a flowchart of the procedures that realize the functionsof the diagnostic device of the present invention.

When a diagnosis program is started, in an instruction presentationprocedure (S20), instruction information to the patient is read out fromthe diagnosis program and displayed in the display device 25. Then, inan identification code reading procedure (S21), the identification codeof sound signals of a word or sentence to be presented is read out fromthe diagnosis program. In a sound signal selection procedure (S22), thesound signals of the word or sentence are selected and read out from thesound source signal storing portion 22, according to the identificationcode. The read-out sound signals are converted to the Noise VocodedSpeech Sound data in the Noise Vocoded Speech Sound conversion procedure(S100) as described above. Then, in a stimulus presentation procedure(S23), the Noise Vocoded Speech Sound data is converted to analog soundsignal and presented to the patient as a stimulus through the headphone.When the patient listens to the Noise Vocoded Speech Sound and inputsrecognized contents, the diagnostic device stores the input responsedata in a response storing procedure (S24). In an end determinationprocedure (S25), it is confirmed, referring to the diagnosis program,whether or not the presentation of a series of stimuli has ended, and ifthe result is NO, the procedure goes back to (S20), and moves to thenext stimulus presentation. This procedure is repeated so that a set ofdiagnosis program menus made of a series of questions can be executed.In the end determination procedure (S25), if the result is Yes, thismeans that a test made of a set of stimulus series is completed, andtherefore the procedure moves to (S26). Here, the disease of the patientis determined or an intermediate determination is made, based on theresponse results and the disease database. As a result of the responseanalysis up to that point, when further proceeding with the nextdiagnosis, the results is NO in an analysis result determinationprocedure (S27), so that the procedure goes back to the instructionpresentation procedure (S20), and proceeds with the subsequent diagnosisprogram. When the results is YES in the analysis result determinationprocedure (S27), this means that diagnosis results are obtained, so thatin a diagnosis output procedure (S28), the estimated disease or relateddata are output to a printer or display for the diagnostician and thusdiagnosis ends.

The stimulus sentences, response sentences, disease database that areused here are the same as those described in Embodiment 1.

Embodiment 8

In the case of diagnosis of a person with hearing impairment, if theperson has a poor sensitivity to a certain frequency band, the frequencycharacteristics that compensate for a reduction in the sensitivity tothat frequency can be provided to the frequency characteristics of eachband filter. In FIG. 1, the sound signals of all of the four frequencybands are replaced by frequency band noise signals, but sound signals ofa part of the frequency bands are not supplied to the multiplyingportion 3 but supplied directly to the adder 6, so that sound signalcomponents can be left. Also with respect to each of the frequency bandswhose sound signal components are to be left, a correction correspondingto degradation of the dynamic range or the frequency characteristics ofhearing disorder may be performed.

In all of the above-described embodiments, the number of the bandfilters of the band filtering portions 1 and 2 is 4 as a typicalexample. However, the number thereof is not limited to 4 and can be 4 orless or more. The number of the frequency bands that is suitable,depending on the situation, can be used.

A recording medium on which a program for a procedure for a diagnosticmethod of the present invention is recorded includes ROM, RAM, flexibledisks, CD-ROM, DVD, memory cards, hard disk on which the program isrecorded. Furthermore, the medium includes communication media such astelephone networks, and transmission paths. A CD-ROM that stores theprogram of the diagnostic method of the present invention or a CD-ROMthat stores disease database is mounted on a personal computer, so thatthe personal computer can be a diagnostic device of the presentinvention. Furthermore, the program of the diagnostic method of thepresent invention is downloaded into a personal computer through atelephone network or the like, the response collection results are sentto a remote disease database center and the determination results of thedisease may be obtained from the center and output.

INDUSTRIAL APPLICABILITY

The present invention relates to a diagnostic device and a diagnosticmethod that employ Noise-Vocoded Speech Sound obtained by subjecting atleast one frequency band signal of a sound signal to noise and. Inparticular, the present invention relates to diagnostic devices anddiagnostic methods suitable to diagnose a disorder of people who mayhave a neural disorder.

1. A diagnostic method comprising: outputting a Noise-Vocoded SpeechSound signal that is obtained by dividing at least one portion of asound signal into a frequency band signal and subjecting the frequencyband signal to noise; receiving a response of a patient; and diagnosinga disease of the patient based on the response; wherein theNoise-Vocoded Speech Sound signal is a word or a sentence in which acomponent of a sound source signal is subjected to noise is generatedby: extracting a frequency band signal with a predetermined frequencyband from at least one portion of the sound signal by a first bandfiltering procedure having a plurality band filtering procedures;extracting an amplitude envelope of each frequency signal by an envelopeextracting procedure; generating a frequency band noise signalcorresponding to the predetermined frequency band from a noise sourcesignal by a second band filtering procedure having a plurality of bandfiltering procedures; multiplying the amplitude envelope of eachfrequency signal by the frequency band noise signal in a multiplyingprocedure; and accumulating outputs obtained by the multiplyingprocedure in an adding procedure.
 2. The diagnostic method according toclaim 1, wherein a disease is estimated with reference to diseasedatabase, based on information corresponding to the output Noise VocodedSpeech Sound signal and the response.
 3. The diagnostic method accordingto claim 1, wherein at least one of a number of the band filteringprocedures for division into frequency band signals and a frequency of afrequency band boundary can be changed, at least depending on thelanguage.
 4. The diagnostic method according to claim 1, wherein atleast one of a number of the band filtering procedures for division intofrequency band signals and a frequency of a frequency band boundary canbe changed through automatic language recognition.
 5. The diagnosticmethod according to claim 1, comprising a sound signal extractingprocedure for extracting only a sound component from a sound signal,wherein the Noise Vocoded Speech Sound signal is obtained by convertingat least one portion of the extracted sound component to a Noise VocodedSpeech Sound signal.
 6. A diagnostic device for executing the methodaccording to claim
 1. 7. A diagnostic method comprising: outputting aNoise-Vocoded Speech Sound signal that is obtained by dividing at leastone portion of a sound signal into a plurality of frequency band signalsand subjecting the frequency band signals to noise; receiving a responseof a patient; and diagnosing a disease of the patient based on theresponse; wherein the Noise-Vocoded Speech Sound signal is a word or asentence in which a component of a sound source is subjected to noise isgenerated by: extracting a frequency band signal with a predeterminedfrequency band from at least one portion of the sound signal by a firstband filtering procedure having a plurality band filtering procedures;extracting an amplitude envelope of each frequency signal by an envelopeextracting procedure; generating a frequency band noise signalcorresponding to the predetermined frequency band from a noise sourcesignal by a second band filtering procedure having a plurality of bandfiltering procedures; multiplying the amplitude envelope of eachfrequency signal by the frequency band noise signal in a multiplyingprocedure; and accumulating outputs obtained by the multiplyingprocedure in an adding procedure.
 8. The diagnostic method according toclaim 7, wherein a disease is estimated with reference to diseasedatabase, based on information corresponding to the output Noise VocodedSpeech Sound signal and the response.
 9. A diagnostic device forexecuting the method according to claim 7.